A video conference system built in an internet protocol (IP) network is provided. The system has a multimedia capturing unit, a DECT telephone, and a video conference terminal apparatus. The DECT telephone is utilized to perform video conferencing with the video conference terminal apparatus by receiving and transmitting sounds. The DECT telephone is further utilized to control the video conference terminal apparatus to capture a target image in the video signals from other users in the video conference. The video conference terminal apparatus updates the phonebook image in the phonebook database thereof with the target image.